Emulsifier burner for hydrocarbons and water with mechanical spraying a controlled flame and having an anti-atmospheric pollution effect



' Oct. 13, 1970 R. E. G EMULSIF'IER BURNER FOR HYDROGARBONS AND WATER WITH MECHANICAL SPRAYING A CONTROLLED FLAME AND HAVING AN ANTI-ATOMOSPHERIC POLLUTION EFFECT Filed July 2, 1968 UERIKN 3,533,717

United States Patent 01 lice 3,533,717 Patented Oct. 13, 1970 Int. Cl. 1 23c 5/08 US. Cl. 431-182 1 Claim ABSTRACT OF THE DISCLOSURE A burner is provided for producing an emulsion of water and liquefied fuel to insure the gasification and complete combustion in a furnace. The burner comprises a casing removably fixed on one face of the furnace hearth containing an atomizer and a carrier therefor, there being an emulsifier incorporated in the carrier and rigidly fixed thereto for sliding in an adjustable manner in the casing and adapted to cooperate with an adjacent combustion chamber in which air is passed under pressure.

The present invention relates to a burner with mechanical spraying, which produces, with or without re-cycling, an emulsion of water and liquid fuel and ensures the gasification and complete combustion at a controlled rate of the combustible elements without producing either fouling or half-burnt particles, even with a very small excess of air (2 to This results in continuous maintenance of the optimum conditions of efiiciency, increases speed of thermal exchanges by radiation and convection, and also the elimination of atmospheric pollution due to solid residues.

It is known that for the great majority of adjustments of fuel-oil burners, the percentages of C0,, are generally 10 to 13% and the corresponding excess air amounts to 55 to 20%; the baccarach index of opacity of the exhaust gases is of the order of 2 to 6, and the necessary frequency of soot removal from the boilers is from 1 to 5 weeks, according to the regulation considered.

The sooting-up which necessitates frequent cleaning of the boilers or heat exchangers increases the cost of maintneuance and facilitates corrosion due to the formation of sulphuric acid which condenses on the cooler parts.

The best burners on industrial regulation can give 14 to 14.5% of CO with a baccarach index of opacity of the smoke of 2 to 3, irrespective of the kind of fuel employed, but by injecting into the boiler hearths the fuel corresponding to two-thirds or three-quarters of the rated output of the boiler. On the other hand, if there is introduced all the fuel necessary to cause the boiler to produce the energy corresponding to its rated output there is obtained in a very short time, an index of opacity of the exhaust gases which is unacceptable in view of the regulations for pollution of towns, and a very rapid fouling of the tubes or collectors which necessitates very frequent soot-removal.

The invention has for its object to eliminate these disadvantages, and to this end, the invention utilizes the combustion of fuel emulsified with Water and sprayed mechanically.

The invention has also for its object the adaptation to the process according to the invention of all types of burners with mechanical spraying, and the construction of new burners without having to change the standards of construction, output and pressure of the pumps,

output of the motors, automatic working, electric or gas ignition.

The invention has also for its object the utilization,

of burners with mechanical spraying and automatic operation for industrial purposes in order to produce special flames filling the furnace without tongues and maintaining an automatically-controlled neutral atmosphere. These furnaces may be metal-melting furnaces, thermal treatment, annealing or tempering furnaces with direct flame or with a muflle, furnaces for baking earth or enamels, stoves, autoclaves, tar-kneading machines, lime kilns, furnaces for baking dolomites, ovens for bakers, pastrycooks and delicatessen.

Briefly, the invention utilizes a conventional burner With mechanical spraying, or produces a burner with mechanical spraying, both provided with an emulsifier so as to treat the fuel oil in emulsion, which facilitates spraying and results in the complete combustion of the carbon of the hydrocarbons by gasification.

This burner comprises various conventional means of supply of combustion air: pressure distribution or regulation cones with or without helicoidal grooves, discs provided with slots enabling the flame to be stabilized at the nozzle of the burner, conventional air shutters, either on the upstream or the downstream side of the turbine. This type of burner is constructed for all outputs, for all operations and rates of working, and the adaptation of an emulsifier to this kind of equipment presents no ditficulty for any type.

The burner according to the invention can be constructed with an atomizer carrier and an emulsifier rigidly fixed together, which makes it possible in certain cases to use very light hydrocarbons as fuel, these being only capable of forming unstable emulsions: petrols, parafiins, gas-oils.

The combustion of an emulsion of oil in water or water in oil makes it possible to obtain, under suitable conditions, a complete combustion of the carbon contained in the fuel, by modifying the chemical reactions. The presence of nascent oxygen and hydrogen resulting from the decomposition of water, converts the heavy elements in the centre of the flame more rapidly to volatile hydrocarbon elements which burn. Considering each droplet as an independent source of fire, the reaction conditions necessary for total gasification are maintained throughout the whole volume of the flame and for this reason, the invention eliminates the tongues of flame of pure fuel-oil and the decreasing temperature zones as the distance from the burner increases.

The total factor of emission by radiation is increased and can easily reach its maximum value when the excess air is entirely or almost entirely eliminated. This advantage makes it possible to obtain the theoretical temperature of a definite mixture, either for the purpose of finding the maximum possible heat transmission or of maintaining uniformly a precise controlled temperature. This temperature depends on the percentage of Water contained in the mixture.

The emulsifying burner with mechanical spraying, according to the invention, permits:

(1) Hydrocarbons to be emulsified with water, if so desired Without re-cycling, by utilizing the standard equipment of an existing burner and adding thereto an emulsifier fed by the existing pump without changing the output of the motor;

(2) The emulsion produced to be atomized under good conditions at lower temperatures than with pure fuel (in the case of heavy or viscous fuel) and at a lower pressure, or in the case of burners fitted with an atomizer-carrier-emulsifier, of burning emulsions of very light hydrocarbons such as petrol, parafiin, gas-oil;

(3) This method of gasification of the carbon to be applied by previous emulsion at the mechanical-spray burner, with the object of combating atmospheric pollution by solid residues;

(4) The known combustion properties of emulsions of water and liquid fuel to be applied to this type of burner in order to obtain flames of homogeneous uniform temperature without tongues, and controlled under neutral or oxidizing atmosphere at will.

This advantage makes possible the equipment of industrial furnaces or stoves for fully automatic working, with mechanical-spray burners. Depending on the case, the invention provides non-corrosive atmospheres close to neutral (heat treatment of metals, combustion in boilers, stoves, autoclaves, etc.) or oxidizing atmospheres (furnace baking, treatment of certain steels, refractories, etc.);

The radiation of the flame to be increased and the maximum energy to be introduced into a hearth so as to' reach the rated outputs of the boilers or to exceed it in the case of certain boilers but without increasing the opacity of the exhaust gases, at the same time ensuring complete combustion, which may enable the output of a boiler to be increased by to 30%, depending on its design;

(6) Combustion to be effected with a minimum excess of air and therefore to reduce the formation of sulphuric acid, and, when so required, permitting this acid to be completly neutralized by the addition of water-soluble products, reacting during the course of the combustion so as to form neutral compounds which are deposited on the metal walls and thus serve to protect them.

In the case of heavy fuels which contain much sulphur, combustion in an oxidizing medium can produce H 80 but this acid is then dissociated by reaction with active hydrogen so as to form S0 and water or to form with the additive in solution or suspension in the emulsified mixture, a corresponding neutral salt. It is therefore possible to completely eliminate the discharge of 80,-; into the atmosphere by using a suflicient quantity of reactant to neutralize it.

Briefly, the burner comprises, in a casing fixed or removably mounted on one face of the hearth, an emulsifier and an atomizer-carrier which may be rigidly fixed together, or an emulsifier atomizer-carrier, diffusion accessories and air regulation by conventional means.

One construction according to the invention will now be described with reference to the single figure of the accompanying drawings, given by way of non-limitative example.

The fuel-Water emulsifier-burner according to this embodiment of the invention comprises, in a casing 1 of generally cylindrical form and removably fixed by means of screws 2 on the face 3 of the hearth, an emulsifier 4 with its supply 5 and an atomizer carrier 6 with an atomizer 7 and its return 8, the whole being rigidly fixed to a cup 9; this cup 9 may have the shape shown in the drawing, or it may have other shapes, for example frustoconical. The emulsifier 4 is entirely conventional and its details of construction form no part of the present invention.

The whole system is mounted slidably in the "casing 1, for example, as shown in the drawing, by means of three studs 11 at 120, and a rear slide (not shown) or a rear regulating screw 12. The cup 9 may be provided with one or more ignition electrodes 13 and with inclined fins 14 which may be adjustable if so required.

The casing 1 is provided with an air-intake 16, mounted obliquely on the axis of the casing, for example tangentially as shown, so as to give the air a helicoidal or whirling movement, which is increased as required by the fins 14. The equipment according to the invention further comprises a combustion chamber 17 in the form of a nozzle having a convergent portion 18 and a divergent portion 19 placed level with the casing 1 in the hearth 3, the convergent portion 18 being close to and opposite the cup 9 and leaving an air passage 20. When so required, an inspection orifice 21 is formed in the chamber for a photo-electric control cell 22 or an inspection sight-hole.

If so required, the atomizer-carrier 6 may be provided with a plurality of jets 7, arranged symmetrically.

It will be noted that the design of the assembly: atomizer-carrier, air regulation and support, can constitute a single removable unit which permits the nozzle of the burner to be completely freed in order to facilitate maintenance.

The regulation of air is obtained by moving the mobile assembly with respect to the casing 1 so as to vary the free section of passage 20 permitting the supply of combustion air necessary for the combustion according to the flow-rate of the jet 7 and the flame having the desired form, temperature and power. A position is defined by an adjustable stop for full power and another for low power in the case of two rates of operation. The displacement may be gradual in the case of modulated rates.

The flow-rate and the method of distribution of air determine the total or incomplete, rapid or slow gasification of the carbon, which is a function of the physical and chemical conditions of the reaction medium. These conditions vary according to the resultant temperature of the gasification chamber, the quantity of water emulsified with the fuel and the nature of the products dissolved or put in suspension in the water in order to obtain the flame desired, the given intensity of radiation or the production of combustible gases utilized at a distance for baking or treatment in certain industrial furnaces.

In normal operation, the flame is stabilized at the nose of the burner and all the gasification of the carbon must take place during the travel defined by the gasification chamber 17. The shape of this chamber depends on the value of the angle formed by the extension of the terminal cone of the cup 9, and on the pressure of air admitted to support combustion in the zone 20. A frustoconical form which is close to the conventional venturi gives good results.

In the case of small burners for domestic heating, the monobloc type is often desired, in which all the control and supply apparatus are rigidly fixed on the body of the burner. In this case, the air-supply casing 16 may be replaced by that of a turbine provided with a driving motor, and may carry the control apparatus and coupling accessories for the supply of water and fuel. A hinge may be provided on the casing 1 so as to free readily the line of jets and the throat of the hearth.

The burner according to the invention has the advantage of permitting a neutral combustion and a variable flame temperature, depending on the percentage of water and fuel, which ensures perfect combustion of the carbon and completely eliminates solid unbumt particles. In addition, the high percentages of CO (15 to 15.8%) for the fuel-oil eliminate the risk of corrosion and prevent the formation of H On the other hand, the possibility of adding either salts of calcium, magnesium, or other elements, depending on the object desired, in solution or in suspension in the water, makes it possible to obtain neutral residues which are added to the asphalts or other substances contained in the fuel-oil and form dry, feeblyadherent deposits which do not foul the boilers.

The domestic and industrial exchange elements or exchangers thus always remain clean and the maintenance for soot removal amounts to an annual operation instead of a frequency which might be from a few days to a fortnight. On the other hand, the cleanliness of the exchange elements, the thermal conductivity of the combustion gases, which is higher in the case of emulsified fuel than for pure fuel, due to the presence of water in larger quantities, the high percentages of CO obtained and the reduction in temperature of the residual gases, result in the fact that the real efficiencies obtained are very high.

If the higher calorific power is considered, we thus approach 95% on the lower calorific power without recuperators of heat.

On the other hand, the total gasification of the carbon by the combustion of the emulsified fluid is accompanied by the total dissociation of the water comprised in the emulsion, which results in the presence in the reaction mixture of nascent hydrogen and oxygen. These active elements are in the presence of active carbon produced at the moment of cracking of the heavy elements :-'0f the fuel. The usual chain of unstable radicals formed during the course of the usual combustion becomes modified, and in consequence the gasification of the carbon is more complete. The flame produced by this method of combustion of fuel is similar to that of a gas and approaches that which is obtained with coal gas or natural gas. All the useful efficiencies obtained are in general considerably higher than the best efiiciency obtained at the present time. There are no longer any unburnt particles, the carbon is completely converted to C0 The uniformity of distribution of air in the first phase of the combustion determines the homogeneity of the reaction medium.

The theoretical temperature of the combustible mixture is obtained together with the maximum percentage of CO 15.6 to 15.8, and to this end, the cup 9 of metal or refractory substance is designed so as to distribute the air symmetrically into the flame and comprises, at the extremity nearest to the flame, shapes which are either straight or incurved, permitting the flow of air to be correctly directed towards the centre of the gasification chamber 17, in such manner that a continuous depression zone is produced level with the jet so as to suck the atomized fuel mixture towards the combustion air in the gasification chamber, which defines the total combustion.

It will be quite clear to those skilled in the art that, starting with a conventional burner, by adding to it and outside it, except in the case of very light hydrocarbons, the apparatus for supplying and treatment of the fuel in emulsion, by adapting the rate of combustion to the gasification chamber, there can be obtained results equivalent to those given above in respect of the emulsifier burner previously described. a

It will of course be understood that the means employed have been described by Way of examples only and not in any limitative sense, and that without departing from the scope of the invention, those skilled in the art can make modifications according to the conditions of application and can vary the forms of construction.

What I claim is:

1. In a furnace having a hearth, a burner for hydrocarbons and water with mechanical spraying, and having a controlled flame and producing an anti-atmospheric pollution efiect, said burner comprising a casing removably fixed on one face of the furnace hearth, an emulsifier, an atomizer-carrier and a cup, means supporting said emulsifier, atomizer-carrier and cup as a rigidly fixed unit, means on said cup engaging said casing for slidable adjustment on said casing to enable the unit to slide in an adjustable manner in said casing, a combustion chamber of convergent-divergent shape placed opposite said cup and means for causing air under pressure to pass obliquely into said casing and thence between said cup and said convergent portion.

References Cited UNITED STATES PATENTS 1,914,355 6/1933 Argyle et a1 431-184 X 2,033,010 3/1936 Russell 431-4 2,158,521 5/1939 Nahigyan 431186 X 2,274,818 3/1942 Zink 431-182 X 2,847,063 8/1958 Reed et al 431186 X i CARROLL B. DORITY, 111., Primary Examiner U.S. Cl. X.R. 431186 

